working memory model

• Baddeley and Hitch noted significant problems with the multi-store model of memory because it was overly simplistic and emphasized the role of rehearsal as being critical for learning. This lead them to develop their own with an active working memory.
• there are three components to the working memory model: the central executive, the phonological loop, and the visuo-spatial sketchpad
• There are two slave systems inn the working memory that deal with the verbal and visual information: the phonological loop and the visuo-spatial sketchpad.
• The central executive deals with the running of the memory system
• The role of the working memory is to temporarily store and manipulate information being used.
• We rely on the working memory for many functions, such as remembering telephone numbers and lists, comprehending sequences of words in the form of sentences, mental calculations and reasoning. However working memory is fragile and susceptible to distraction, overload and overwork.
• The central executive is a limited capacity component involved in general processing.
• The central executive can be described as a homunculus, little man, with a supervisory role in deciding how the two slave systems should function.
• The central executive is is modality free
• the central executive is...

  an attentional controller with the ability to focus, divide and switch attention
• modality free


  able to process different forms of information
• The working memory model was by...

  Baddeley and Hitch (1974)
• the phonological loop deals with the temporary storage of verbal inforrmation
• The phonological loop has two components: The articulatory loop and the phonological store
• The phonological store can hold a limited amount of verbal information for a few seconds but this can be extended if the information is subvocalized or refreshed using the articulatory loop
• The phonological store can be used to explain the phonological similarity effect, where it is more difficult to remember similar sounding words and letters than dissimilar sounding ones
• The phonological store relies on acoustic encoding for storage(Baddeley 1966)
• The articulatory rehersal system can be used to explain the word length effect because longer words fill up the limited capacity of the articulatory system more than shorter words resulting in the decay of words positioned earlier in the word list.
• The visuo-spatial sketchpad temporarily hold and manipulates visual and spatial information.
• The visuo-spatial sketchpad deals with information either directly through observing or through retrieving through LTM.
• The visuo-spatial sketchpad maintains and integrates visual and spatial information
• the visuo-spatial sketch pad is made up of the inner scribe and the visual cashe
• spatial span - corsi block tapping test


  Blocks on a screen that light up in a sequence repeatedly increasing in difficulty and number. Error frequency increases with the number in the sequence suggesting that spatial memory has a limited capacity.
• Williams syndrome is a condition where individuals show normal language ability but have impaired visual and spatial ability. This offers clinical evidence for separate visuospatial and phonological subsystems.
• The case study of KF gives support to the idea that the working memory has two sub systems to deal with visuospatial and verbal information as his phonological store was impaired but his visual memory was intact.
• Paulesu et al (1993)


  Different regions of the brain were activated doing different tasks. Using a PET scan they found that Broca's area was activated during a subvocalized rehearsal task and that the super marginal gyrus was activated when the phonological store was being used. This neuroimaging evidence gives support for the phonological loop and it subcomponents.
• dual task experiments

  performing two tasks simultaneously that involve one or more slave systems
• Baddeley and Hitch (1976)


  Did a dual task experiment that required participants to complete two visual tasks simultaneously. The performance was impaired when they did the two visual tasks together as they were competing for the limited resources in the visuo-spatial sketchpad. When doing a visual and verbal task the performance was unaffected. This study offers evidence for separate visual and verbal slave systems.
• Klauer and Zhao (2004)


  Visual memory tasks were disrupted by visual interference and spatial tasks were more interrupted by spatial interference. This gives evidence for separate components to the visuo-spatial sketchpad.
• Darling et al (2007)


  Showed participants 30 white squares randomly placed on a black screen with one square containing the letter 'p'. Participants had to recall either the location or the appearance of the letter. They then experienced spatial or visual interference. They found that spatial interference disrupted spatial memory but not memory for appearance and visual disruption affected memory for appearance but not location. provides evidence for separate visual and spatial systems.
• The working memory model doesn't explain how the subcomponents interact with each other or our long term memory. This led to the addition of the episodic buffer in 2000.
• Baddeley (2000) added the episodic buffer which is a limited capacity storage system that can integrate information from subcomponents and retrieve information from the long-term memory.